Location: Subtropical Plant Pathology Research
Project Number: 6034-22000-045-013-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2019
End Date: Jun 30, 2024
Objective:
Train canines to detect the whitefly-transmitted Tomato yellow leaf curl virus (TYLCV) and Squash vein yellowing virus (SqVYV), and the thrips-transmitted Tomato spotted Wilt Virus (TSWV) and Tomato chlorotic spot virus (TCSV) in infected plant material and viruliferous insects.
a. Initial training and validation of four canines will be conducted in an experimental greenhouse and small field plots using both artificially inoculated and naturally infected plants.
b. Trained detector dogs will be tested in commercial production fields.
c. Trained detector dogs will be tested in commercial vegetable transplant production houses.
Approach:
The procedures for training, evaluating and deploying canine detector dogs for pathogen detection have been extensively detailed for other viral pathogens. In brief, the initial training begins with a proprietary sensitization process. Canines are rewarded for alerting on the proper target by providing a few minutes of play with the handler. Dogs will be sensitized via a series of randomized (blind) diseased and non-diseased sources to ensure the canines are alerting correctly at a high degree of accuracy. Typically this is done in randomized field trials, recording environmental conditions during each trial, and re-randomizing between each validation. We plan to train multiple dogs to detect individual whitefly- and thrips-transmissible viruses in a range of hosts. Moreover, because the sensitivity and accuracy of detection across host species and cultivars may not be the same – presumably because the volatile composition or concentration may differ – advanced training will be conducted in both an experimental greenhouse (to be constructed with first year funds) and field plots on a larger collection of infected and non-infected cultivars and species to ensure that the canines are not preferentially excluding infections in less familiar cultivars, species, or weed hosts. The initial imprinting is anticipated to take 4 months to complete.
Once trained, dogs will be field-tested in commercial vegetable plantings. They will be tasked to locate infected plants within plantings of selected crops, and will be used to scout field perimeters to locate potential reservoir weed hosts. All “hits” will be evaluated visually and by ELISA and/or Polymerase chain reaction (PCR) to determine the infection status of the plants. Dogs will also be deployed in transplant houses. Vegetable transplants are produced in mass in greenhouse settings prior to transplanting into production fields. Canine interrogation techniques can take advantage of this high-density to screen large numbers of transplants rapidly. Detection of virus-infected transplants in production houses has obvious logistic and economic advantages. By intercepting infected material before it is widely disseminated and planted, large-scale epidemics can be avoided, thereby preventing potentially enormous production losses. Culling infected transplants is a simple, inexpensive and rapid prevention method so long as infected plants can be detected at an early and possibly subclinical stage of infection. This practical training is anticipated to take 4-6 months to complete.
